This month we're
beginning a new department here in "Shutterbug" we call Point
of View. Photography is a wide-ranging field that engenders passion in
its practitioners, and like all great forms of expression creates opinions
formed through experience and reflection. In its early days one of the
great debates was: Is Photography Art? This was the subject of many essays
and heated discussions among players and spectators. Today, issues such
as film vs. digital, format choices, the validity of computer generated
images, photography as exploitation or revealer, and even the merits of
ink jet vs. silver prints cause similar debate. We are opening this department
up to readers, manufacturers, and retailers--in short, everyone who
lives and breathes photography and who has an opinion about anything affecting
Here's how to get involved: write us an e-mail at firstname.lastname@example.org
or send us a letter with a proposed topic and a synopsis of your idea.
Once approved, we'll ask you to send us about 500-1000 words on
the subject chosen. The idea here is not to push any product or wave any
flag, but to create discussion about photo and imaging topics of the day.
We reserve the right to edit whatever you send in, although we will never
edit intention or opinion but only for length and, hopefully, for clarity.
We reserve the right to publish your work on our web site as well, so
you can join the archives and be a resource for opinion for years to come.
We'll kick-start the department with the following discussion and
hope that it gets your juices flowing. So, get thinking and writing and
share your Point of View.
Long brewing, the debate between
advocates of digital and film has grown livelier, and often testier of
late, with advocates of the two mediums going head to head in forums,
studios, and camera clubs around the country. What once was thought to
be peaceful coexistence might be turning into an either/or situation,
with votes being cast in the dollars spent. Although digital's rise
has been meteoric, there's no question that film cameras and film
practitioners still prevail. But with the recent wave of high-megapixel
digital SLRs, and the coming affordable products in this class, more photographers
will be undergoing their own internal struggles as to which way to go.
With that in mind I thought it might be a good time to set down some of
my own thoughts about the two forms of imaging. Whether you believe that
it's an either/or situation of course depends on how you approach
photography and what you want to accomplish in your work. But what began
as a local skirmish fought in the fields of commercial photography has
now spread to just about every aspect of our craft and trade. The opinions
expressed are anecdotal and experiential, rather than the result of any
sort of scientific test. They are intended to further debate rather than
come to some final conclusion. We'll begin with some background
on the different ways in which these systems capture and hold light.
Both film and CCD or CMOS sensors are receptors that aim to replicate
the blink of a human eye. They gather light's energy and coalesce
the stimulus into a coherent image, one that can be read again and again
as a moment frozen in time. They are aided in this task by the lens, which
focuses the light at or near a point on the plane of the receptor, and
the shutter and lens diaphragm, which control the volume of light that
is the exposure. When light strikes film it causes a change in the metallic
silver salts that reside (in color film) within the various color-recording
layers. This change is in direct proportion to the amount of light that
strikes the film. The latent image is then developed in chemical baths
that convert the change to various densities of silver deposit, which
(again, in color film) is replaced with dyes, again in proportion to the
amount of light that initially struck the film. The color of the recorded
light is trapped within these various recording layers, a sandwich that
when combined forms a color image that represents in some fashion the
color and brightness of the original scene.
While grossly oversimplified, this scenario is typical of how film records
an image, although each type of film will differ in how it responds to
light depending on its dyes (the various color saturation and contrast
personality of each film) and its speed, or overall sensitivity to light.
One of the chief advances in film photography over the last decade has
been the lessening of the tradeoff between light sensitivity and characteristics
usually associated with a good quality image, such as grain, sharpness,
and fidelity of color rendition. In creating various film "personalities,"
filmmakers have also refined the art to be able to produce emulsions that
respond to color as a recorder of neutral, vivid, or even very high color
saturation. In short, we are in the Golden Age of film technology.
The digital sensor is a complex microchip that is composed of photo sites,
electrical receptors that when exposed to light create a charge. After
exposure this charge is transferred to a microprocessor that integrates
the resultant signal and converts it to binary codes. The microprocessor
may be on the chip itself or a separate device within the workings of
the system. Each photo site becomes the source of an address made up of
these codes. This address identifies color, brightness, and tone and,
with integration, creates a relationship between the various sites in
terms of contrast, color balance, and tonal spread to create an image.
Grain And Pixels: Does The
While it might seem that the pattern of silver-halide grains spread through
a film emulsion are analogous to these photo sites, the grains actually
behave in quite different ways. Although work has been done to make the
grains in silver halide uniform, they still have a fairly random shape
and tend to spread among each other during and after development. Chips
are purely industrial creatures, thus more uniform in their pattern. The
pixels--as these photo sites are known--are not random in shape,
but are square, hexagonal, or other proprietary shape, but are nonetheless
uniform throughout. Color is created by two principle methods. The most
prevalent is the overlaying of a checkerboard of red, green, and blue
filters that serve as light passes and traps to give the resultant signal
a certain color character, all of which is later integrated in processing.
The other, the Foveon chip in particular, is a layering of red, green,
and blue filters that are more akin to the architecture of film, although,
again, an integration process forms color. This difference in the image
forming process, and the random vs. near architectural structure, in part
defines and differentiates the look of a silver (or dye) formed image
and a digital image.
Advantage: Tie. If we accept that every medium has its own "look"
we just accept that look and move on. If we expect digital to emulate
the photographic look and use that as criteria then photo quality ink
jet printers make the argument that indeed it can. While film is at its
highest quality ever, digital images can be startling in their sharpness,
smoothness (continuous tone), and color rendition. Indeed, some say that
digital can and will rival the resolution of film.
Resistance To Deterioration:
Expiration And Fog
Film, like milk, has an expiration date after which images made on it
will not be as good as when the film is "fresh," or more properly,
"mature." Undeveloped film, even when fresh, is subject to
change by exposure to heat, radiation, and other forces of nature before
exposure and can fade, crack, wrinkle, or become scratched after exposure
and development. Film will also become damaged when subject to intense
airport screening or even when allowed to sit in high-altitude locations.
In short, it's fairly fragile.
While the digital chip is not subject to "fogging" or other
detrimental factors there is some problem with what is euphemistically
called "pixel death." In essence, the pixels can "go
dark" and will not record any image information. Generally this
can be counteracted by something called "pixel mapping," which
in essence uses algorithms to make assumptions about what "should"
reside there in a given subject or scene. Pixels may go dark on their
own, due to manufacturing defects, or more likely go "blind"
by repeated exposure to intense amounts of light. And sensors, being charged
electrical devices, can attract dust and like anything else will not suffer
the insult of injury without being damaged. But they are not subject to
fogging radiation like film and the digital image resides in code, not
in an emulsion spread on a sometimes too-fragile base.
Advantage: Digital. This may be said out of ignorance, as we are not
sure (or we are not told) about a CCD or CMOS sensor's eventual
rate of deterioration. But having had too many film rolls go out of date,
a few damaged by airport scanners, and more than a few shot years back
just lose color and density, the fragility of film makes this a point
in the digital column. A digital file can be copied over and over to save
it if necessary without any information loss; we simply can't say
the same about film.
Exposure Tolerance: Overexposure
When subject to gross overexposure the metallic grains upon development
will exhibit a growth beyond their intended borders, yielding a halo effect
around intense highlights and a "blocking up" that can cause
image information to go awry. While films do have an anti-halation backing
to prevent light scattering, this does not prevent the intense rendition
of highlight areas due to gross overexposure. In addition, if subject
to too much development the silver salts in the latent image will go amok
and cause blocking as well, resulting in gross densities that mask the
image or highlight areas of the image in a deep shroud, making printing
and even viewing difficult. In color film this overexposure or overdevelopment
may also cause color crossovers, a condition that even the most radical
filtration during printing might not be able
There is no development per se of the digital image, but there is a similar
and even greater danger with overexposure. Think of the photo site as
a well with a limited depth into which you pour too much water, or light.
The well begins to spill over and there is no place for the water (light)
to run except onto other sites. Although advanced digital systems have
a drain, if you will, that will begin to handle the electrical spillover,
many do not or handle it with less sophistication. The result is known
as "blooming" and may create a halo around highlights, throw
off color (artifacts), and even create comets of light within the image
itself. These overexposed areas become "blanks" in the image
file. There is even some talk that consistent and gross overexposure of
a digital sensor can cause pixel blindness, discussed earlier.
Advantage: Film. Even taking into account that slide films are equally
intolerant of overexposure, the majority of film shot today is negative
film, thus photographers are spared the indignity of not being able to
handle highlights. Though too much density is certainly not good, all
but the most blown out highlights can be printed through to yield detail
Exposure Tolerance: Underexposure
And Low Light
When a film is underexposed the shadow areas lose separation and darker
shades blend to black. If underexposure is gross colors begin to shift
and there is an overall loss of image fidelity.
Digital sensors will also suffer in their image quality output when underexposed.
Interestingly, an image that might seem underexposed on preview in the
camera's monitor may have enough information to be useful when later
"processed" in an image-editing program. And digital sensors
seem to outdo film in the amount of information they can gather in low
light. This has been noticed in many situations and leads to the conclusion
that digital sensors are much more light efficient in low light and/or
handle underexposure in a better fashion than film.
Advantage: Digital. Add to this the fact that you can boost contrast
on every frame, rather than have to push an entire roll, and digital is
just more versatile in situations where there are a variety of lighting
levels in a shooting session.
Film exhibits major problems if not properly developed. This is the most
consistent reason why film can fail to fulfill its potential, even if
the initial exposure was correct. While most labs do a good job, some
have bad days or are consistently poor in what they deliver. This can
be discouraging to photographers, as they often blame themselves for what
is really a third-party screw-up. Digital images are processed inside
the camera or after with image-editing programs. If the camera delivers
poor processing it's a bad camera or if the image-editing program
is poorly used it will yield bad images. But at least it's in the
hands of the photographer.
Advantage: Digital. It's the photographer's responsibility,
and at least they can take the credit or the blame.
Exposure latitude is defined as the degree of over- and underexposure
in which a useable image can be recorded. This does not mean that images
of equal quality will be delivered throughout this range; it indicates
the limits of tolerance of the media.
Negative films are generally thought to be able to handle a range of five
stops of light, with the distribution being three stops overexposed and
two stops of underexposure. This is one reason why single-use cameras
work. Direct positive films are much narrower in their tolerances, due
to the reversal process to which they are subjected. That tolerance is
about one stop overexposure and one to two stops of underexposure. In
practice, digital sensors are more akin to slide films in the way they
behave. This is due to the "well" analogy described earlier.
What occurs is that when grossly overexposed there seems to be a wiping
out, or interference of the signal, and once subject to such conditions
the pixel seems incapable of recovering and delivering any useable image
information. The latitude on the underexposure side is a bit better.
The implication of this is that photographers should expose digital by
biasing that exposure toward the highlights, common practice among slide
shooters. Those who have worked with negative film and practice the tried-and-true
maxim of exposing for the shadows and developing (or printing) for the
highlights will find it simply does not work well with digital. Negative
films that are overexposed may have too much density in the highlights,
but unless this is a gross overexposure these highlights can be "fought
through" for details and tone. Slide shooters know that too much
exposure on the highlights yields blank film, or at the least no texture
in highlight areas.
So, one truism for exposure with digital is to expose or bias exposure
for the highlights. Digital does offer an out to this dilemma. If exposing
for the highlights results in underexposure of the shadow areas (which
will occur in high-contrast situations) another exposure can be made of
the same scene (assuming the camera is fixed on a tripod) for the shadows
and the images can be combined later. This is like making separation masks
in the darkroom with film, a tricky proposition known to veteran darkroom
workers but not easily accomplished in the typical home darkroom. But,
as mentioned, the tolerance for underexposure in digital is quite wide.
Advantage: Film. The five-stop range is just too great for digital
to compete with, although digital techniques can overcome a high-contrast
situation better than film, given some digital darkroom expertise.
Lighting Conditions: Flat
Flat light is defined as ambient light with little or no contrast differential
throughout the scene. With film it can result in rather dull images. The
classic response to this is to increase developing time to increase image
contrast, known as "pushing." Of course, if roll film is being
used the entire roll must be subject to the push, meaning that for effective
results photographers would have to either shoot the entire roll under
the same overall lighting condition or swap rolls in and out to work under
different lighting conditions. The oft-proposed Zone System for rollfilm
photographers works with this premise of swapping rolls.
For digital, dull light is no problem, as it is quite simple to alter
image contrast for each frame at the time of exposure or after when the
image is processed further in the computer. Contrast enhancement is one
of the real values of working in digital, as each pixel area can be changed
with ease or the entire image can be boosted to higher contrast through
the use of in camera or later in computer controls. Anyone who has worked
with the Levels controls in Photoshop has a revelation about contrast
Advantage: Digital, just because it's so much easier and more
convenient than when working with roll film.
All film is subject to an effect known as the failure of reciprocity,
which occurs with long exposure times. Reciprocity in exposure means that
if you add or subtract a stop of exposure (in effect, doubling or halving
the exposure time) you will get a corresponding increase or decrease in
density of one stop on the film, given proper development. When you exceed
a certain exposure time (which varies according to the film, and can be
anywhere from beyond 1 sec to beyond 10 sec) reciprocity fails and you
have to add exposure time to compensate to get the desired density. The
factor (or addition to the required time) gets greater as exposure further
exceeds the limit of reciprocity effect.
There is no equivalent effect with digital sensors, but long exposures
do result in a low-energy recording that will yield increased noise in
the image. Noise is akin to grain in film, but can be better described
as the flecks of visual static that appear like snow in the image. These
flecks are known as artifacts, and they can have color tinges around their
edges as well. Many cameras have what is known as a noise reduction function
that can be turned on or automatically kicks in (if activated) whenever
the system detects excess noise in an image, or when a long exposure time
is used. This is a microprocessor function that detects and removes noise
by comparing the artifact to the surrounding pixels and changes the noise
to match those pixels, rather like a smoothing effect. This improves the
image but the processing time can be quite long, and as the image is processing
no other images can usually be recorded.
Advantage: Tie. Pick your poison--longer exposure times for film
or noise reduction functions in digital. At least film doesn't get
those pesky flecks, although the color cast can get weird.
Filters And Contrast Control
In Black And White
If working with black and white film, altering the values recorded within
the scene through the use of color filters can control contrast. These
filters block the complementary color light and pass the same color light.
The classic use is to mount a yellow filter to deepen the blue in the
sky, a green filter to enhance the forms and patterns of foliage, and
a red filter to differentiate between red and green forms (or to enhance
the red subject in any scene, which might not be differentiated without
the filter). In addition, polarizing filters can be used to control contrast
created by non-conducting material reflections.
All images recorded by digital sensors are color images. They are composed
of three "channels" of Red, Green, and Blue (RGB). If black
and white is the desired result, conversions allow the enhancement of
one or another of these channels (or a combination of them all) or the
outright elimination of one or another channel. The ease of conversion
and the ability to manipulate these channels in an image-editing program
eliminates the need for the use of filters for contrast control when shooting
for monochrome images.
Advantage: Digital. There's little need for contrast control filters
because you're always shooting in RGB and monochrome conversions
can be customized with ease.
Films are manufactured with a certain color balance, with "daylight"
(5500Þ Kelvin) being the norm. Color balance refers to how the film
will behave in ambient light and how true color (without overall cast
or bias) will record when the film is exposed under various lighting conditions.
For example, if a daylight film is exposed inside a room lit by incandescent
bulbs the image will record with an amber cast. This occurs because the
light source is deficient in blue.
Our eyes do not see this deficiency, as we adapt to the light and order
colors accordingly. Film cannot do this as it is made to respond to light
with color rendition as if all light is daylight (or "white"
light with the full spectrum included). There are classes of films with
tungsten balance (either 3400 or 3200ÞK) that can be used with artificial
continuous light sources. But these light sources must be of a specific
nature for the color to be dead on. The only true method of getting true
color under a variety of light sources is to use a color temperature meter
that recommends color-correcting filters over the lens. Of course, a certain
color bias in a scene can add mood and flavor, and color correcting, for
example, the dazzling warmth of the setting sun's affects on subjects
is not desirable.
Digital sensors have the ability to correct for any color temperature
light source through a processing step known as white balance. The sensor
itself does not do this, but it is added during post-exposure processing
in the camera. Setting a certain white balance (of which there are usually
five or six available) will place the processing system within a range
of white balance (thus Kelvin temperature) settings. Custom white balance
allows the photographer to be more precise, if desired, and to set the
color balance for an exact color balance, acting like a color temperature
meter without the need for adding color-correcting filters over the lens.
In addition, color moods can be enhanced by using white balance as a color
enhancing filter to add a touch of warmth (using "cloudy"
white balance) or cool blue (using tungsten white balance) to the image.
In essence, digital cameras literally eliminate the need for filters for
color correction and enhancement.
Advantage: Digital. Many cameras allow you to work as if you have a
color temperature meter on board, with built-in filtration for mood effects
Film allows for high framing rates, with some film cameras shooting as
fast as 10 fps (frames per second). The highly sophisticated motors in
these cameras react to pressure on the shutter release when the camera
is set for a continuous shooting mode. This is a great advantage for sports
and action photographers. These framing rates are accompanied by extremely
fast autofocusing and autoexposure functions and make film cameras totally
responsive to a photographer's reflexes and eye. Of course, shooting
a roll of film in 3-4 sec means that you better be good at changing rolls
or have a few back-up cameras on hand if the action keeps on happening.
Digital cameras can only make an exposure when the sensor has cleared
the previous image and after image processing has sent the image to the
converter and memory card. The processing time will vary according to
the speed of the processor and the size of the image file (resolution).
If functions such as noise reduction are used this processing time will
increase. Some cameras feature an on-board buffer, where image information
is stored before processing, allowing higher framing rates than would
otherwise be available. The capacity of the buffer determines how many
exposures can be stored (modified by the size of the image) and how fast
the image information can be shunted to it. The storage area does not
hold images, per se, but image information that must be processed for
it to become an actual image file. This means that the images have to
be processed at one point, and when the buffer is full it will halt photography
until the images have been processed and moved to the memory card. This
means that cameras that offer higher frames per second recording do so
only in a set period of time. The specs will read, for example, 3 fps
for 10 sec, or a limit of 30 frames at a high burst rate. Again, these
specs will be modified according to the resolution of the recorded image.
Advantage: Film cameras, but only if you need high burst rates that
can be accomplished within 36 frames. But the processing time of buffered
images gives film cameras an advantage as well, as most seasoned photographers
can change rolls faster than all those images can be processed. True,
pro sports photographers have made the switch to digital, but for all
the rest of us film cameras still have an edge.
Image Capacity Per Roll
Film is spooled in a set number of exposures per roll--24 or 36 exposures
for 35mm film and perhaps 12 or 15 exposures with 120 film, depending
on the frame's aspect ratio in the medium format camera used.
The capacity of the digital "film," memory cards, is dependent
on two factors--the resolution and compression of the recorded image
and the capacity of the memory card itself. The resolution determines
the size of the file. If, for example, an image is made at the full capacity
the 3-megapixel chip can deliver the file size will be about 9MB (megabytes).
If the image is uncompressed (TIFF mode) and a 32MB card is loaded then
three images can be fit on the card. If the resolution is changed, or
if the resolution and compression ratio are changed, then the card will
hold proportionately more images. The numbers can be confusing, but following
the frame countdown on the camera's LED panel will reveal all.
Advantage: Tie. At least with film you know how many images you have
left, but if you're shooting low resolution or high compression
images with digital and have a fairly high-capacity card you can get hundreds
of images per card. On the other hand, if you have a 16MB card with a
5-megapixel camera and want uncompressed images you better go out and
get yourself a high-capacity card. Using that 16 is like going out with
one sheet of film in a holder with a 4x5 camera. So even though the card
is reusable you better have a few as back-ups when you travel.
Economics: Cost Of Media
This is a bit of a no-brainer. Each time you want to photograph with a
film camera you have to buy a roll of film and pay for processing. A digital
memory card is reusable, although we have yet to hear just how many cycles
of exposure and download it will handle. But with card prices dropping
every six months and capacities going up there's no question that
economics come down on the side of digital. It's like using throwaway
batteries or rechargeables--the numbers just add up.
Advantage: Digital, hands down.
To see the results of your work with film requires that the film be developed,
an often-hushed interval where more fingers are crossed than more photographers
care to admit. Of course, one of the key advantages of digital photography
is the immediate feedback it provides on aesthetics (pose, point of view,
and composition) and exposure (contrast and tonal spread). The former
is a bit overplayed as an advantage, as the LCD monitor is often a poor
indicator of focus and even exposure due to its small size and low resolution.
In playback mode, however, many digital cameras allow for two methods
of being able to make a better judgment call. One is a zoom function that
can bring up cropped areas of the image full frame. The other, and perhaps
more important function, is the histogram read-out. A histogram is a visual
map of tonal spread and is perhaps the best way to judge how well you
have exposed the image. Some cameras also have an verexposure warning
function, where areas that have received too much exposure will flash
with a user-selectable color to indicate an exposure problem. However,
any information you get from the LCD is often blocked by its poor readability
in bright daylight. Using an accessory hood or viewing the LCD in shade
is always best.
Advantage: Digital. Seeing results right away might be what sells more
digital cameras than any other factor, given that you're not trying
to see what you got in bright light.
You knew we had to get to this one eventually, and here is where the most
debate occurs. Many factors influence image quality in both film and digital,
including the quality of the lens, the exposure, the steadiness of the
camera when exposure is made, the quality of light, and so forth. Perhaps
some sanity can be brought to the discussion by bringing in the issue
of resolution and compression on digital vs. the fixed resolution, if
you will, of film.
In digital, resolution and compression are key elements in obtaining quality
images for a particular end use. Notice the emphasis on end use. Unlike
film, where a set frame size records the image, thus determines enlargeability
within fairly loose bounds of quality, a digital image recording can be
altered to, in effect, be applied to very specific end uses. A smaller
image file that might fall apart when enlarged to an 8x10 print will be
more than sufficient for a smaller print or as an image that will not
see paper but be used for monitor viewing only. And a larger image file
that will do well in an 8x10 print will be overkill for a monitor image.
By manipulating file size with resolution and compression choices, efficient
use of memory card capacity and ultimately hard drive or other storage
capacity can be made. If in doubt as to the intended use the image should
be photographed at the best potential quality setting, using either low
compression JPEG or TIFF or RAW file format. The size can always be made
smaller later. But if the intended use is for small prints or e-mail or
web images, then a smaller file size can be used for the initial recording.
So, like film of a certain size, the sensor can also only deliver an image
of a certain size and quality end use. The megapixel count of the sensor
and how you preprogram the settings determine the high end of what the
image can be used for. Even 1- and 2-megapixel cameras yield perfectly
fine results for the web and e-mailing images.
In the end, image quality is based on a very personal feeling about what
an image should look like and how you think and feel that tonal values
and colors should spread throughout the frame. Given that both types of
media are used in optimum fashion and that the prints or output are created
by competent craftspeople, there could be a tossup. But in the end it's
up to you as to what will stir your visual instincts and passion. Digital
has certain distinct advantages in capture and processing potential, but
film still holds the imagination of many photographers who are not just
being old-fashioned or stubborn about adopting new technology. Digital
has added a lot of creative fun and new challenges to the art and craft
of photography. But is it time to say that it's ready to replace
film? Only you can decide that.